Label-Free Optical Sensing and Medical Grade Resins: An Advanced Approach to Investigate Cell–Material Interaction and Biocompatibility

: The Corning Epic® label-free (ELF) system is an innovative technology widely used in drug discovery, immunotherapy, G-protein-associated studies, and biocompatibility tests. Here, we challenge the use of ELF to further investigate the biocompatibility of resins used in manufacturing of blood filters, a category of medical devices representing life-saving therapies for the increasing number of patients with kidney failure. The biocompatibility assays were carried out by developing a cell model aimed at mimicking the clinical use of the blood filters and complementing the existing cytotoxicity assay requested by ISO10993-5. Experiments were performed by putting fibroblasts in both direct contact with two types of selected resins, and indirect contact by means of homemade customized well inserts that were precisely designed and developed for this technology. For both types of contact, fibroblasts were cultured in medium and human plasma. ELF tests confirmed the biocompatibility of both resins, highlighting a statistically significant different biological behavior of a polyaromatic resin compared to control and ion-exchanged resin, when materials were in indirect contact and soaking with plasma. Overall, the ELF test is able to mimic clinical scenarios and represents a promising approach to investigate biocompatibility, showing peculiar biological behaviors and suggesting the activation of specific intracellular pathways

Novel bioprinted 3D model to human fibrosis investigation

Fibrosis is shared in multiple diseases with progressive tissue stiffening, organ failure and limited therapeutic options. This unmet need is also due to the lack of adequate pre-clinical models to mimic fibrosis and to be challenged novel by anti-fibrotic therapeutic venues. Here using bioprinting, we designed a novel 3D model where normal human healthy fibroblasts have been encapsulated in type I collagen. After stimulation by Transforming Growth factor beta (TGFβ), embedded cells differentiated into myofibroblasts and enhanced the contractile activity, as confirmed by the high level of α − smooth muscle actin (αSMA) and F-actin expression. As functional assays, SEM analysis revealed that after TGFβ stimulus the 3D microarchitecture of the scaffold was dramatically remolded with an increased fibronectin deposition with an abnormal collagen fibrillar pattern. Picrius Sirius Red staining additionally revealed that TGFβ stimulation enhanced of two logarithm the collagen fibrils neoformation in comparison with control. These data indicate that by bioprinting technology, it is possible to generate a reproducible and functional 3D platform to mimic fibrosis as key tool for drug discovery and impacting on animal experimentation and reducing costs and time in addressing fibrosis

Human Adipose Mesenchymal Stromal/Stem Cells Improve Fat Transplantation Performance

The resorption rate of autologous fat transfer (AFT) is 40–60% of the implanted tissue, requiring new surgical strategies for tissue reconstruction. We previously demonstrated in a rabbit model that AFT may be empowered by adipose-derived mesenchymal stromal/stem cells (AD-MSCs), which improve graft persistence by exerting proangiogenic/anti-inflammatory effects. However, their fate after implantation requires more investigation. We report a xenograft model of adipose tissue engineering in which NOD/SCID mice underwent AFT with/without human autologous AD-MSCs and were monitored for 180 days (d). The effect of AD-MSCs on AFT grafting was also monitored by evaluating the expression of CD31 and F4/80 markers. Green fluorescent protein-positive AD-MSCs (AD-MSC-GFP) were detected in fibroblastoid cells 7 days after transplantation and in mature adipocytes at 60 days, indicating both persistence and differentiation of the implanted cells. This evidence also correlated with the persistence of a higher graft weight in AFT-AD-MSC compared to AFT alone treated mice. An observation up to 180 d revealed a lower resorption rate and reduced lipidic cyst formation in the AFT-AD-MSC group, suggesting a long-term action of AD-MSCs in support of AFT performance and an anti-inflammatory/proangiogenic activity. Together, these data indicate the protective role of adipose progenitors in autologous AFT tissue resorption

Synthesis and free radical scavenging activity of 4-(2H-1,2,4-benzothiadiazine-1,1-dioxide-3-yl)-2,6-bis(1,1-dimethylethyl)phenols

4-(2H-1,2,4-benzothiadiazine-1,1-dioxide-3-yl)-2,6-bis(1,1-dimethylethyl)phenols (1-11) were prepared by cyclization of the corresponding 3,5-bis(1,1-dimethylethyl)-4-hydroxy-N-2-(sulphamoylphenyl)benzamides (12-22). Compounds 1-22 were tested as free radical scavengers by reaction with DPPH using UV and ESR spectrometry and the formation of stable phenoxy radicals by their oxidation with lead tetraacetate was also studied. Copyrigh

Distribution of minor and trace elements among Italian chondritic meteorites

The cobalt, nickel, zinc, selenium, rubidium and cesium content was determined in eight Italian chondritic meteorites by destructive neutron activation analysis. The chemical procedure involves only a few steps: sample dissolution, radiochemical separation of the elements on inorganic adsorbers (copper grains and zinc ferrocyanide)andonDowex 2x8 anionic resin. Element contents are reported and discussed. Precision and accuracy of the analytical method are given as well. Results and average class values are compared with existing values in the literature. Possible correlations between pairs of elements (Co - Ni, Zn - Se and Rb - Cs) in the examined chondrites, were investigated and discussed

A novel 2-Dimensional correction method for mm-Wave Cartesian I/Q Modulators

This paper proposes a self-corrected In-phase/Quadrature-phase (I/Q) digital Cartesian modulator. The modulator is comprised of double balanced Gilbert cells to mitigate code dependent input and output impedances. Transistor-level simulations in 28 nm bulk CMOS demonstrate a static error vector magnitude (EVM) of −35 dB at 79 GHz carrier while providing 9.5 dBm peak output power with ~19% drain efficiency. Transistor level analysis shows that the linearity is limited by the transconductance (gm) I and Q input code dependency. To address this dependency a self-contained 2-dimensional correction technique is proposed. The proposed correction method improves the EVM from −35 dB to −42.5 dB without compromising the output power, power efficiency and occupied silicon area. The proposed solution enables linear and power efficient transmitters (TXs) for mm-Wave applications

A MEMS Reconfigurable QUAD-Band Class-E Power Amplifier for GSM Standard

In this work we present a reconfigurable mid-power Class-E Power Amplifier (PA) [1,2] operating at ~900MHz and ~1800MHz (GSM standard [3]) realized hybridizing one chip manufactured in AMS 0.35μm CMOS technology and one MEMS sub-network. The CMOS chip realizes the active part of the circuit, whereas the MEMS block (realized in FBK technology) implements a reconfigurable impedance Matching Network (MN) that transforms the 50Ω antenna load to the 12Ω impedance required by the PA in order to deliver 20dBm output power in both the GSM operating frequency bands. The prototype of the MEMS/CMOS PA we realized delivers 20dBm with 38% and 26% drain efficiencies at 900MHz and 1800MHz, respectively, demonstrating to be a feasible option compared to standard commercial solutions